1. Field of the Invention
The invention relates to a novel method of detecting certain radiant energy, such as X-rays or .gamma.-rays and somewhat more particularly to a method of detecting such energy via a crystalline bismuth oxide compound.
2. Prior Art
Bismuth oxide compounds containing small amounts of other oxide additives are known, for example, from "Journal of Research of the National Bureau of Standards - A. Physics and Chemistry", Vol. 28A, No. 2, March-April 1964, pages 197-206. This publication discloses processes for preparing various bismuth oxide compounds.
Further, Bi.sub.12 GeO.sub.20 and Bi.sub.12 SiO.sub.20 monocrystals have been grown for a considerable length of time since these monocrystals have good piezoelectric properties. It has also been pointed out in "Journal of Crystal Growth", Vol. 1, 1967, pages 37-40, that the bismuth oxide monocrystals have photoconductivity properties (which can be easily seen from the color of the monocrystals) in the wavelength range of about 0.5 to 7 .mu.m, with the usual drop in sensitivity for the photoconductivity effect with shorter wavelengths.